/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the  "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id$
 */
package wx.xml.xalan.xalan.trace;

import org.w3c.dom.Attr;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import wx.xml.xalan.xalan.templates.ElemTemplateElement;
import wx.xml.xalan.xalan.transformer.TransformerImpl;
import wx.xml.xalan.xml.utils.QName;

/**
 * Parent class of events generated for tracing the
 * progress of the XSL processor.
 *
 * @xsl.usage advanced
 */
public class TracerEvent implements java.util.EventListener {

    /**
     * The node in the style tree where the event occurs.
     */
    public final ElemTemplateElement m_styleNode;

    /**
     * The XSLT processor instance.
     */
    public final TransformerImpl m_processor;

    /**
     * The current context node.
     */
    public final Node m_sourceNode;

    /**
     * The current mode.
     */
    public final QName m_mode;

    /**
     * Create an event originating at the given node of the style tree.
     *
     * @param processor  The XSLT TransformerFactory.
     * @param sourceNode The current context node.
     * @param mode       The current mode.
     * @param styleNode  The stylesheet element that is executing.
     */
    public TracerEvent(TransformerImpl processor, Node sourceNode, QName mode,
                       ElemTemplateElement styleNode) {

        this.m_processor = processor;
        this.m_sourceNode = sourceNode;
        this.m_mode = mode;
        this.m_styleNode = styleNode;
    }

    /**
     * Returns a string representation of the node.
     * The string returned for elements will contain the element name
     * and any attributes enclosed in angle brackets.
     * The string returned for attributes will be of form, "name=value."
     *
     * @param n any DOM node. Must not be null.
     * @return a string representation of the given node.
     */
    public static String printNode(Node n) {

        String r = n.hashCode() + " ";

        if (n instanceof Element) {
            r += "<" + n.getNodeName();

            Node c = n.getFirstChild();

            while (null != c) {
                if (c instanceof Attr) {
                    r += printNode(c) + " ";
                }

                c = c.getNextSibling();
            }

            r += ">";
        } else {
            if (n instanceof Attr) {
                r += n.getNodeName() + "=" + n.getNodeValue();
            } else {
                r += n.getNodeName();
            }
        }

        return r;
    }

    /**
     * Returns a string representation of the node list.
     * The string will contain the list of nodes inside square braces.
     * Elements will contain the element name
     * and any attributes enclosed in angle brackets.
     * Attributes will be of form, "name=value."
     *
     * @param l any DOM node list. Must not be null.
     * @return a string representation of the given node list.
     */
    public static String printNodeList(NodeList l) {

        String r   = l.hashCode() + "[";
        int    len = l.getLength() - 1;
        int    i   = 0;

        while (i < len) {
            Node n = l.item(i);

            if (null != n) {
                r += printNode(n) + ", ";
            }

            ++i;
        }

        if (i == len) {
            Node n = l.item(len);

            if (null != n) {
                r += printNode(n);
            }
        }

        return r + "]";
    }
}
